- It seems that our joy cannot find files if a path given with -I
  contains relative directory markers '..'.  We should fix that, as
  it's generally expected to work.

- It Would Be Nice™ if the search included both the current working
  directory and the directory from where the include is being issued.

- joy-mode.el:
  * comment insertion/deletion
  * indentation
  * function documentation lookup
  * function template insertion

